Swap to foreground tab when following links that open in a new tab/window in VR Shell.

chrome/browser/android/vr_shell/vr_web_contents_observer.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/android/vr_shell/vr_web_contents_observer.h"
 
 #include "chrome/browser/android/vr_shell/ui_interface.h"
 #include "chrome/browser/android/vr_shell/vr_shell.h"
 #include "chrome/browser/ssl/security_state_tab_helper.h"
 #include "components/security_state/core/security_state.h"
@@ skipping 63 matching lines @@
 }
 
 void VrWebContentsObserver::WebContentsDestroyed() {
   vr_shell_->ContentWebContentsDestroyed();
 }
 
 void VrWebContentsObserver::WasHidden() {
   vr_shell_->ContentWasHidden();
 }
 
+void VrWebContentsObserver::WasShown() {
+  vr_shell_->ContentWasShown();
+}
+
+
 void VrWebContentsObserver::MainFrameWasResized(bool width_changed) {
   vr_shell_->ContentFrameWasResized(width_changed);
 }
 
 void VrWebContentsObserver::RenderViewHostChanged(
     content::RenderViewHost* old_host,
     content::RenderViewHost* new_host) {
   new_host->GetWidget()->GetView()->SetIsInVR(true);
 }
 
 }  // namespace vr_shell